OTTAWA, Canada (CNN) -- President Bush dismissed concerns Tuesday about strained ties between the United States and Canada, thanking those Canadians who turned out to wave "with all five fingers" during his first official visit.

Bush said he understood that many Canadians opposed the U.S.-led invasion of Iraq in 2003 but added: "I'm the kind of fellow who does what he thinks is right, and will continue to do what I think is right."

Bush and Prime Minister Paul Martin said Tuesday that they agreed to work "in a practical way toward common goals," including tightening border security and resolving trade disputes.

But Martin expressed frustration with a continuing U.S. ban on Canadian cattle, imposed after a case of mad cow disease was discovered in Washington state in 2003, and the dispute over a 27 percent tariff the Bush administration imposed on Canadian softwood lumber imports in 2001.

On the cattle issue, Martin said scientific tests have "clearly demonstrated that a decision should be taken, and a favorable decision to Canada should be taken as quickly as possible."

"This has been studied to death," he said.

Bush said he understood Martin's frustration but that U.S. law requires the White House Office of Management and Budget to review proposed Agriculture Department regulations before his administration can lift the ban.

"I fully understand the cattle business. I understand the pressures placed upon Canadian ranchers," he said. But he noted, "There's a bureaucracy involved. I readily concede we've got one."

Asked about polls that suggested U.S. and Canadian public opinion drifting apart on major issues such as the war in Iraq, Bush said he hadn't seen those surveys. But he added, "We just had a poll in our country when people decided that the foreign policy of the Bush administration ought to stay in place for four more years."

"It's a foreign policy that works with our neighbors. Trade between our countries has never been stronger," he said. "But it's a foreign policy that also understands that we've got an obligation to defend our security."

Addressing another international issue, Bush called Iran's recent decision to temporarily suspend its uranium enrichment program a good first step, but he said the United States wants to see a permanent halt to the program. (Full story)

Bush said he received a "very warm and hospitable" welcome in Ottawa.

But outside the joint news conference, a large crowd of demonstrators engaged in shoving matches with police and waved signs calling Bush an "international terrorist" and demanding he end "the massacre in Iraq." Others bluntly said, "Go home." (Full story)

Bush had planned to visit Canada in 2003, but the trip was scrubbed after then-Prime Minister Jean Chretien refused to contribute troops to the invasion of Iraq.

Both countries said Iraq was not a factor in the decision to cancel the trip, but it was not rescheduled until Chretien retired in December.

Further aggravating the situation were critical comments from Chretien's spokesman, who called Bush a "moron," and a member of Parliament from the prime minister's center-left Liberal Party, who, referring to what she called "damn Americans," concluded, "I hate those bastards."

The spokesman was fired, but the MP, Carolyn Parrish, was re-elected to her suburban Toronto seat in June. She has continued her criticism, telling reporters after Bush's re-election that the results showed Americans were "completely out of step" with the rest of the world.

The Liberal Party, now led by Martin, kicked Parrish out of its parliamentary caucus this month after she was shown stomping on a Bush doll during a television spoof.